Cooling system and methods

ABSTRACT

Disclosed are systems and methods for facilitating the cooling of electronic devices. In one embodiment, a cooling system includes a core having a plurality of surface channels configured to facilitate the transport of a working fluid. The cooling system can include a cover configured to cover the surface channels, and further configured to couple to the core to form a leak proof seal with an interference fit. In some embodiments, the interference fit can be the result of a thermal fitting. The core can be a metal core printed circuit board. The core can be configured to be in thermal communication with a printed circuit board. In certain embodiments, the surface channels are in communication with a fluid inlet and a fluid outlet; the fluid inlet and the fluid outlet can be placed on a side of the core opposite a side of the core having the surface channels.

FIELD

Embodiments of the invention generally relate to systems and methods forcooling electronic devices. In particular, one embodiment of theinvention relates to a core having a plurality of channels, and a coverconfigured to cover the channels. The channels are configured totransport a fluid. The core and the cover are configured to provide aleak proof seal through an interference fit.

BACKGROUND

The ever growing placement of heat generating components into electronicdevices means that heat dissipation from electronic devices becomes moreimportant. U.S. Patent Application Publication No. 2012/0106083Adiscloses a liquid cooling system including a plurality of coolingmodules, a plurality of heat exchangers, and a plurality of conduitsfluidly connected to the plurality of cooling modules and the pluralityof heat exchangers. The cooling module is thermally connected to aheat-generating electronic component on a circuit board of theelectronic system and cools the electronic component by a coolantflowing in the cooling module.

U.S. Pat. No. 4,612,978 discloses a device for cooling a high-densityintegrated circuit package. The device described in U.S. Pat. No.4,612,978 includes a board for inserting an IC package and another ICand a heat exchanger part for covering the board and sealing the IC. Thecoolant passing through the heat exchanger part carries away the heatassociated with the operation of the IC. The heat exchanger partincludes a housing having a bottom plate made of a high heat transfermaterial, a membrane portion including a wire mesh, and a coolantchamber having a contact plate deformable so as to be in contact withthe upper surface of the IC. A plurality of heat transfer spheres arefilled in the coolant chamber.

There is still a need in the relevant technology for systems and methodsthat facilitate the cooling of electronic components and/or devices.

SUMMARY OF THE INVENTION

In one aspect, the invention is directed to a printed circuit board(PCB) cooling system. The system can include a core configured to bethermally coupled to at least one heat producing electronic component onfirst side of the core; one or more channels placed on a second coreside of the core, the first side of the core and the second side of thecore being opposite each other; a cover configured to couple to the coreand to cover the one or more channels; the core and the cover arecoupled to form a substantially leak proof seal via a thermalinterference fit; and, when the core and the cover are coupled, the oneor more channels can be used to transport a working fluid.

In one embodiment, the core is a metal core printed circuit board. Insome embodiments, the channels comprise a fluid outlet and a fluidinlet. In some embodiments, the fluid outlet and the fluid inlet areplaced on the first side of the core. In certain embodiments, the coverincludes a peripheral, raised wall configured to couple to a peripheraledge of the core. In one embodiment, the thermal interference fitresults from cooling the core and fitting the core inside the cover. Insome embodiments, the thermal interference fit results from expandingthe cover by heating the cover, and then fitting the core inside thecover while the cover is expanded. In certain embodiments, the channelsare configured to transport water as the working fluid.

In another aspect, the invention concerns a method of manufacturing acooling system. In one embodiment, the method includes providing a corehaving a first core side and a second core side; providing surfacechannels on the second core side; providing a cover configured to coverthe surface channels; and coupling the core and the cover with aninterference fit. In some embodiments, the core is a metal core printedcircuit board. In certain embodiments, the first core side is configuredto be in thermal communication with a printed circuit board.

In one embodiment, a distribution of the surface channels on the secondcore side is determined, at least in part, on a distribution ofelectronic components placed on the first core side. In someembodiments, the surface channels are coupled to a fluid inlet and to afluid outlet, and th fluid inlet and the fluid outlet are placed on thefirst core side.

In certain embodiments, the cover comprises a peripheral raised wallconfigured to couple to a peripheral edge of the core. In oneembodiment, coupling the core to the cover with an interference fitincludes shrinking the core by cooling it, then placing the core insidethe cover. In some embodiments, coupling the core to the cover with aninterference fit includes expanding the cover by heating it, thenplacing the core inside the cover.

Yet another aspect of the invention is related to a cooling systemhaving a core with a first core side and a second core side, the firstcore side and the second core side being opposite each other; one ormore channels placed on the second core side; a cover configured tocouple to the core and to cover the one or more channels; the core andthe cover are coupled to form a substantially leak proof seal with aninterference fit; and, when the core and the cover are coupled, the oneor more channels can be used to transport a working fluid.

In one embodiment, the first core side comprises a printed circuitboard. In some embodiments, the first core side is configured to be inthermal communication with a printed circuit board. In certainembodiments, the interference fit is the result of a thermal fitting.

Additional features and advantages of the embodiments disclosed hereinwill be set forth in the detailed description that follows, and in partwill be clear to those skilled in the art from that description orrecognized by practicing the embodiments described herein, including thedetailed description which follows, the claims, as well as the appendeddrawings.

Both the foregoing general description and the following detaileddescription present embodiments intended to provide an overview orframework for understanding the nature and character of the embodimentsdisclosed herein. The accompanying drawings are included to providefurther understanding and are incorporated into and constitute a part ofthis specification. The drawings illustrate various embodiments of thedisclosure, and together with the description explain the principles andoperations thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the embodiments, and the attendantadvantages and features thereof, will be more readily understood byreferences to the following detailed description when considered inconjunction with the accompanying drawings wherein:

FIG. 1 is a schematic view of a pumping system according to oneembodiment of the invention.

FIG. 2 is a schematic view of cooling system according to one embodimentof the invention.

FIG. 3 is a schematic view of another cooling system according oneembodiment of the invention.

FIG. 4 is a schematic view of yet another cooling system according toone embodiment of the invention.

FIG. 5 is perspective view of an electronic device having a coolingsystem according to one embodiment of the invention.

FIG. 6 is a plan top view of certain components of the electronic deviceof FIG. 5 .

FIG. 7 is plan bottom view of certain component of the electronic deviceof FIG. 5 .

FIG. 8 is a perspective view of certain component of the electronicdevice of FIG. 5 .

FIG. 9 is another perspective view of the component of FIG. 8 .

FIG. 10 is a perspective view of a cooling system according to anotherembodiment of the invention.

FIG. 11 is a cross-sectional view of the cooling system of FIG. 10 .

FIG. 12 is a perspective view of a certain component of the coolingsystem of FIG. 10 .

FIG. 13 is a cross-sectional, perspective view of the component of FIG.12 .

FIG. 14 is a cross-sectional, plan view of the component of FIG. 12 .

FIG. 15 is a cross-sectional, perspective view of a certain component ofthe cooling system of FIG. 10 .

FIG. 16 is a perspective view of a certain component of the coolingsystem of FIG. 10 .

FIG. 17 is a cross-sectional, perspective view of the component of FIG.16 .

FIG. 18 is a perspective view of certain components of the coolingsystem of FIG. 10 .

FIG. 19 is a perspective view of a certain component of the coolingsystem of FIG. 10 .

FIG. 20 is a plan, bottom view of the component of FIG. 19 .

FIG. 21 is a perspective view of the component of FIG. 19 .

FIG. 22 is a cross-sectional, perspective view of the component of FIG.19 .

FIG. 23 is a flowchart of a method of cooling according to oneembodiment of the invention.

FIG. 24 is a flowchart of a method of manufacturing a cooling systemaccording to one embodiment of the invention.

FIG. 25 is a cross-sectional, perspective view of certain components ofa cooling system according to one embodiment of the invention.

FIG. 26 is a perspective view of a certain component that can be usedwith the components of FIG. 25 .

DETAILED DESCRIPTION

The specific details of the single embodiment or variety of embodimentsdescribed herein are set forth in this application. Any specific detailsof the embodiments are used for demonstration purposes only, and nounnecessary limitation or inferences are to be understood therefrom.

Before describing in detail exemplary embodiments, it is noted that theembodiments reside primarily in combinations of components related tothe system. Accordingly, the device components have been representedwhere appropriate by conventional symbols in the drawings, showing onlythose specific details that are pertinent to understanding theembodiments of the present disclosure so as not to obscure thedisclosure with details that will be readily apparent to those ofordinary skill in the art having the benefit of the description herein.

Referencing FIG. 1 , in one embodiment, pumping system 100 can includepump 104 operationally coupled to gas accumulator 108. In someembodiments, pump 104 can be, for example, an electroosmotic (EO) pump.In certain embodiments, gas accumulator 108 can be a chamber configuredto provide a space for facilitating the accumulation of gas 109, whichgas 109 can be produced from, for example, electrolysis during operationof pumping system 100. Accumulation of gas 109 can facilitate mitigatingthe adverse effects of cavitation and/or electrode erosion.

Referencing FIG. 2 , in one embodiment, cooling system 200 can includepump 204 integrally coupled to one or more gas accumulator chambers108A, 108B. In some embodiments, cooling system 200 can include heatexchanger 212 integrally coupled with pump 204. Heat exchanger 212 canbe, for example, a device configured to receive a hot fluid and toradiate heat from the fluid. In one embodiment, heat exchanger 212 canbe, for example, a radiator with fins exposed to ambient air and/orforced cooling air. In certain embodiments, the working fluid can be,for example, water. In some embodiments, cooling system 200 can includea one-way valve (not shown), such as a tesla valve, configured tofacilitate fluid flow in one direction.

In one embodiment, cooling system 200 is made leak proof by usingthermal expansion to seal the joints between pump 204, gas accumulators108A, 108B, and heat exchanger 204. The materials used to build pump204, gas accumulators 108A, 108B, and heat exchanger 204 have suitablecoefficients of thermal expansion to allow the creation of interferencefits between pump 204, gas accumulators 108A, 108B, and heat exchanger204. In one embodiment, said materials can include, for example, copper.

Referencing FIG. 3 , in one embodiment, cooling system 300 can includepump 104 operationally coupled to gas accumulator 108 and to heatexchanger 312. In one embodiment, heat exchanger 312 can be, forexample, a radiator with fins for radiating heat from a hot fluid. Incertain embodiments, cooling system 300 can include core 316operationally coupled to gas accumulator 108 and/or to heat exchanger312. In some embodiments, core 316 can be a metal plate having fluidpassages or channels (not shown) for facilitating transport of a fluidin a circuit from pump 104, to heat exchanger 312, to core 316, to gasaccumulator 108, and back to pump 104. In certain embodiments, thelocation of pump 104, gas accumulator 108, heat exchanger 312, and core316 in the fluid flow circuit can be different. For example, in oneembodiment, core 316 can be positioned between pump 104 and heatexchanger 312. In some embodiments, core 316 can be a metal plateconfigured to support and/or be thermally couple to a printed circuitboard (not shown). In certain embodiments, cooling system 300 can beused with electronic devices having components that produce heat, whichheat can be damaging to said components and, therefore, it is desired toremove the heat.

Referencing FIG. 4 , in one embodiment, cooling system 400 can includecooling system 200 operationally coupled to cover 420. To provide a leakproof seal, in some embodiments, cover 420 is coupled to core 316 via aninterference fit using materials of suitable coefficients of thermalexpansion. In certain embodiments, core 316 can include channels 424that are formed on a surface of core 316 and are covered by cover 420when core 316 and cover 420 are assembled together. Channels 424 can beformed with, for example, CNC techniques, laser-engraving, and/or acidetching.

In one exemplary method of use of cooling system 400, a fluid isintroduced into channels 424. Heat absorbed by core 316 is transferredto the fluid. The heating of core 316 can be the result of, for example,operation of electrical components thermally coupled to core 316.Operation of pump 204 causes fluid to flow from core 316 into gasaccumulator 108A, wherein gas 109 can be collected—gas 109 can beproduced as a result of operation of pump 204 and chemical processes(such as electrolysis) in the fluid. From gas accumulator 108A fluidflows into pump 204 and, subsequently, into or through heat exchanger212, wherein heat from the fluid can be absorbed and dissipated by heatexchanger 212. Next, cooled fluid can flow into gas accumulator 108B,and then flow back into channels 424.

Referencing FIG. 5 and FIG. 6 , in one embodiment electronic device 500can include cooling system 200, core 316, and cover 420. Electronicdevice 500 can include printed circuit layer 504 and electroniccomponents 508. Core 316 can include core fluid outlet 318 and corefluid inlet 320. Core fluid outlet 318 and core fluid inlet 320 aresuitable configured to be coupled to cooling system 200 via, forexample, an interference fit achieved through thermal expansion and/orthermal shrinking. Core 316 can include core periphery side 317.

Referencing FIG. 6 and FIG. 7 , in one embodiment, core 316 can includechannels 424 formed on a side of core 316. In some embodiments, channels424 are operationally coupled to core fluid outlet 318 and to core fluidinlet 320. In certain embodiments, channels 424 are formed on a surfaceof core 316, then cover 420 covers channels 424 when core 316 and cover420 are assembled together. In other embodiments, core 316 can includechannels (not shown) integrated within core 316 to facilitate thetransport of fluid from cooling system 200, to core fluid inlet 320,through the channels of core 316, to core fluid outlet 318, and back tocooling system 200. In some embodiments where core 316 includesintegrated channels, electronic device 500 may not use cover 420.

In certain embodiments, the location, shape and/or size of channels 424can be configured to account for the specific heat production ofelectronic components 508 mounted on core 316. For example, areas ofcore 316 having fewer electronic components 508 would have correspondingareas of channels 424 of lower density of channels 424 and/or smallerchannels 424. Typically, there is a high amount of heat generated at theP-N Junction (not shown) where each electronic component 508 is solderedto a MC-PCBA (metal core printed circuit board assembly) surface. Insome embodiments, channel 424 can be placed directly beneath the P and NJunctions, preferably about 0.5 mm from the heat generating P and NJunctions.

Referencing FIG. 8 and FIG. 9 , in one embodiment, cover 420 can includecover plate 428, which cover plate 428 can include cover plate innerside 430 and cover plate outer side 432. In some embodiments, coverplate 428 can include cover wall 434, which cover wall 434 can be aperipheral wall that is raised all around the perimeter of cover plate428.

Referencing FIG. 7 through FIG. 9 , in one embodiment, the materials ofcore 316 and cover wall 434 are selected to facilitate creating a leakproof seal between core 316 and cover wall 434. In one embodiment, coverwall 434 has a thermal coefficient that allows an expansion of coverwall 434 at a first temperature. Then core 316 can be placed into cover420. Next, as cover 420 cools to a second temperature, cover wall 434shrinks onto core periphery side 317—thereby creating a leak proofinterference fit between cover wall 434 and core periphery side 317. Incertain embodiments, core 316 can be made of a material having a thermalcoefficient such that core 316 shrinks when core 316 is cooled to athird temperature. Then core 316 can be placed inside cover 420. As core316 returns to a fourth temperature, core 316 expands to create aninterference fit between core periphery side 317 and cover wall434—thereby creating a leak proof seal between core periphery side 317and cover wall 434.

Referencing FIG. 10 and FIG. 11 , in one embodiment cooling system 1000can include inlet gas accumulator 110 coupled to electro-osmosis (EO)pump 106. In some embodiments, cooling system 1000 can include heatexchanger 124 coupled to EO pump 106. In certain embodiments, coolingsystem 1000 can include outlet gas accumulator 112 coupled to heatexchanger 124.

In certain embodiments, inlet gas accumulator 110, EO pump 106, heatexchanger 124, and outlet gas accumulator 112 are configured tofacilitate the creation of leak proof seals between the correspondingcoupling components. In one embodiment, for example, inlet gasaccumulator 110 can be configured to be coupled to EO pump 106 via aninterference fit, and the interference fit can be produced through, forexample, thermal expansion of inlet gas accumulator 110 and placing aportion of EO pump 106 in inlet gas accumulator 110. Similarly, heatexchanger 124 can be made of a suitable material having a thermalcoefficient to facilitate the expansion of heat exchanger 124 andplacement of a portion of EO pump 106 in heat exchanger 124.

Referencing FIG. 12 through FIG. 14 , in one embodiment inlet gasaccumulator 110 can include gas accumulator body 113. In someembodiments, gas accumulator body 113 can include gas accumulator inlet114, which gas accumulator inlet 114 can be a protruding portion of gasaccumulator body 113, and which gas accumulator inlet 114 can defineinlet pathway 115 for facilitating a fluid flow into inlet gasaccumulator 110. In one embodiment, gas accumulator body 113 can includepump receptacle 116 configured to couple to a portion of, for example,EO pump 106. Pump receptacle 116 can be configured to define outletpathway 117 for facilitating a fluid flow out of inlet gas accumulator110. In certain embodiments, gas accumulator body 113 can include gascollection chamber 136 configured to provide a space for facilitatingcollection of a gas that can be produced during operation of, forexample, cooling system 1000. In one embodiment, gas accumulator inlet114 can be configured to couple to core fluid outlet 318 (FIG. 6 ) via,for example, an interference fit to provide a leak proof seal.

Referencing FIG. 15 , in one embodiment, outlet gas accumulator 120 canbe configured substantially the same as inlet gas accumulator 110. Insome embodiments, outlet gas accumulator 120 can include gas collectionchamber 137. In one embodiment, outlet gas accumulator 120 can includeheat exchanger receptacle 139 configured to couple to a portion of, forexample, heat exchanger 124. Heat exchanger receptacle 139 can beconfigured to define inlet pathway 148 for facilitating a fluid flowinto outlet gas accumulator 120. In certain embodiments, outlet gasaccumulator 120 can include gas accumulator outlet 119, which gasaccumulator outlet 119 can be a protruding portion of outlet gasaccumulator 120, and which gas accumulator outlet 119 can define outletpathway 121 for facilitating a fluid flow out of outlet gas accumulator120. In one embodiment, gas accumulator outlet 119 can be configured tocouple to core fluid inlet 320 (FIG. 6 ) via, for example, aninterference fit to provide a leak proof seal.

Referencing FIG. 16 through FIG. 18 , in one embodiment EO pump 106 caninclude gas accumulator coupler 138 configured to couple to pumpreceptacle 116. In some embodiments, gas accumulator coupler 138 can bea protruding portion of EO pump 106 that can be fit into pump receptacle116 to create a leak proof seal, which leak proof seal can be made by,for example, creating an interference fit between gas accumulatorcoupler 138 and pump receptacle 116. The interference fit can beproduced through, for example, the use of thermal shrinking and/orexpansion of either or both of gas accumulator coupler 138 and pumpreceptacle 116.

In certain embodiments, EO pump 106 can include membrane holder 122configured to receive and retain membrane 134. In some embodiments,membrane holder 122 can include membrane seat 123 configured to receiveand support membrane 134. In one embodiments, membrane 134 can be madeof alumina, for example. Membrane seat 123 can be defined, for example,by a recessed surface of membrane holder 122. In one embodiment,membrane holder 122 can be configured to couple to heat exchanger 124 toproduce a leak proof seal, using thermal expansion and/or shrinking forexample. In some embodiments, EO pump 106 can include pump fluidpassageway 140 configured to facilitate a flow of fluid through EO pump106. In one embodiment, EO pump 106 can include pump filling port 146configured to facilitate the filling of cooling system 1000 with afluid.

In certain embodiments, membrane holder 122 can include electrodeaccommodators 142, 144 configured to facilitate the location andplacement of electrodes 126, 128. In one embodiment, EO pump 106 caninclude electrode rubber inserts 130, 132 configured to cover at least aportion of electrodes 126, 128.

Referencing FIG. 19 through FIG. 22 , in one embodiment heat exchanger124 can include heat exchanger pump coupler 150 and outlet gasaccumulator coupler 152. In some embodiments, heat exchanger 124 caninclude radiator 154 interposed between heat exchanger pump coupler 150and outlet gas accumulator coupler 152. In one embodiment, radiator 124can include pump filling port 147 configured to facilitate the fillingof cooling system 1000 with a fluid.

In some embodiments, heat exchanger pump coupler 150 can include pumpreceptacle 156 configured to receive and retain membrane holder 122. Incertain embodiments, pump receptacle 156 is configured to provide a leakproof seal with membrane holder 122 via, for example, an interferencefit produced by thermal expansion of pump receptacle 156 and placingmembrane holder 122 into pump receptacle 156. In one embodiment, pumpcoupler 150 can include electrode passageways 158, 160 to facilitateinsertion of electrodes 126, 128 into pump receptacle 156. In someembodiments, pump receptacle 156 can include fluid passageway 162 forfacilitate a fluid flow from EO pump 106 into heat exchanger 124.

In some embodiments, radiator 154 can include one or more fins 164 tofacilitate the radiating of heat from heat exchanger 124. In oneembodiment, radiator 154 can include a plurality of radiator channels166 configured to split a fluid flow through radiator 154 to facilitateexposing the fluid to a greater surface area of radiator 154, to therebyincrease the removal of heat from the fluid by radiator 154.

In one embodiment, outlet gas accumulator coupler 152 can be configuredto couple to heat exchanger receptacle 139 (FIG. 15 ). In someembodiments, a leak proof seal between outlet gas accumulator coupler152 and heat exchanger receptacle 139 can be provided by thermalexpansion of heat exchanger receptacle 139 and placement of outlet gasaccumulator coupler 152 into heat exchanger receptacle 139.

Referencing FIG. 5 through FIG. 22 , an example of using coolingelectronic device 500 is now described. A fluid is introduced intochannels 424 via, for example, pump filing port 146 or pump filing port147. Electricity is applied to electrodes 126, 128, thereby causing anelectroosmotic flow of the fluid through EO pump 106. During operationof electronic device 500, electronic components 508 generate heat, whichheat is absorbed by the fluid in channels 424. The fluid exits core 315via core fluid outlet 318 and enters inlet gas accumulator 110 via inletpathway 115. Gas that can be produced from reactions in the fluid due toelectro-osmosis are accumulated in gas collection chamber 136. The fluidnext moves into EO pump 106 via outlet pathway 117 and into pump fluidpassageway 140.

Under the electro-osmotic effect, the fluid crosses membrane 134 intofluid passageway 162 of heat exchanger 124. The fluid then flows intoradiator channels 166, and heat from the fluid is dissipated intoradiator channels 166 and fins 164. Cooler fluid then flows into inletpathway 148 of outlet accumulator 120. Gas from the electro-osmosisprocess can be accumulated in gas collection chamber 137. The cooledfluid then flows from outlet accumulator 120 into core 315 via gasaccumulator outlet 119 and core fluid inlet 320.

Referencing FIG. 23 , in one embodiment, method 2300 of coolingelectronic components includes providing an EO pump 2305, providing aworking fluid 2310, applying electrical current to the EO pump 2315, andcapturing substantially all the gas 2320 produced by operation of thepump to ensure the gas stays within an enclosure operationally coupledto the EO pump and the working fluid—thereby facilitating or inducingsaturation. In some embodiments, the working fluid can be distilledwater. In one embodiment, the current applied is DC current. In certainembodiments, the gas can be captured by providing hermetically sealedpathways for the working fluid and the gas. Any joints, betweencomponents of a cooling system configured to use method 2300, can besealed (and substantially made leak proof) by, for example, usingthermal fitting between components. Capturing the gas facilitates, amongother things, achieving a chemical equilibrium that reduces and/or(substantially) eliminates the chemical reaction that produces the gas.In some embodiments, reducing said chemical reaction can facilitate, forexample, reducing cavitation and/or electrode erosion. In certainembodiments, gas collection chambers can be provided to facilitatecollecting the gas in a space so that substantially there are no gasbubbles traveling through the cooling pathways of the working fluid. Asgas molecules are produced by the chemical reactions involved inoperating the EO pump, the gas molecules travel through the workingfluid channels and into the gas collection chambers. In someembodiments, the gas collection chambers are configured to allowcontinuous interaction between the gas molecules and the workingfluid—so that a saturation of the gas is achieved.

Referencing FIG. 24 , in one embodiment, method 2400 of manufacturing acooling system can include providing a core with fluid channels 2405,providing a cover configured to couple to the core and to cover thefluid channels 2410, providing an EO pump configured to coupleoperationally to the fluid channels 2415, providing at least one gascollection chamber configured to be operationally coupled to the fluidchannels and/or EO pump 2420, and providing at least one thermal fittingbetween any of the core, cover, pump, and/or at least one gas collectionchamber 2425. In some embodiments, method 2400 can further includeproviding a heat exchanger configured to operationally couple to the EOpump and/or the fluid channels. In one embodiment, the core can be a PCBcore. In some embodiments, the EO pump can be configured to operate withDC current. In certain embodiments, the thermal fitting involves heatingor cooling one component (for example, the cover) to produce acorresponding expansion or a shrinking of the component, then placing asecond component (for example, the core) in an interference fit with thefirst component to ensure a leak proof seal.

In some embodiments, manufacturing cooling system 200, cooling system300, and/or cooling system 400, for example, can involve manufacturingcooling systems that are leak proof through integration of components byusing, for example, 3d printing techniques. Referencing FIG. 4 , in oneembodiment, gas accumulator chambers 108A, 108B, pump 204, and/or heatexchanger 212 can be made leak proof by manufacturing these componentsas a single, integrated piece with 3d printing. Similarly, referencingFIG. 10 and FIG. 11 , in some embodiments, inlet gas accumulator 110 andpump 106 can be made as a single, integrated piece; and outlet gasaccumulator 112 and heat exchanger 124 can be made as a single,integrated piece.

Referencing FIG. 25 , in one embodiment, pump 106A can be provided withpump filing port 146A having a conical shape, with the wider part of thecone being proximal to the external side of pump filing port 146A. Theconical shape is configured to facilitate, among other things, (i) afilling of fluid into system cooling system 1000 a syringe whileallowing air to escape, and (ii) a thermal fitting of port cap 2600 intopump filling port 146A. Similarly, heat exchanger 124A can be providedwith pump filing port 147A having a conical shape, with the wider partof the cone being proximal to the external side of pump filing port147A.

Referencing FIG. 26 , in one embodiment filling port cap 2600 can have agenerally conical shape configured to provide a leak proof seal whenfitted into pump filling port 146A, 147A. In some embodiments, cap 2600can be cooled to cause a shrinking of cap 2600, then cap 2600 can beplaced into pump filling port 146A, 147A. In certain embodiments, pump106A and/or heat exchanger 124A can be heated to cause an expansion ofpump 106A and/or heat exchanger 124A, then cap 2600 can be placed intopump filling port 146A, 147A to form a leak proof seal.

In some embodiments, insertion of metallic components to a metal coreprinted circuit board can be achieved as follows. E-Young' s Modulus;ε-Material Strain; L-Length of material; δ-Change in length; θ-MaterialStress; F-Applied Force; A-Area of pressure; N-Normal Force;Ff-Frictional force; μs-Static coefficient of friction.

In thermal expansion a mass of material decreases in density through theincrease of its volume. In certain materials thermal expansion occursdrastically during a phase change from solid to liquid.

The expansion of a material subjected to a thermal load is directlyproportional to the temperature increase and a material based intrinsicexpansion coefficient. The reverse function also holds true when amaterial is cooled.

To create a tight enough fit reference to stress of materials equationscan be used. σ/ε=E (1); ε=δl/L1 (2); σ=F/A (3). The Young's modulus of amaterial is a constant and, therefore, a given force F over a fixed areaA produces a quantifiable deformation δl.

Given a rod heated to a certain temperature, the rod's length increasesfrom L1 to L2. If the rod is positioned between a column 1 and a column2, it is unable to expand. Since the rod would normally expand to alength L2, it is possible to determine the force that the columns exerton the rod to hold it in place, using equation (2), followed by equation(1), and lastly equation (3) to solve for the applied force F.

Friction is a contact force that opposes motion. In the case of thermalfittings, friction prevents components from being released. Thefrictional force is directly proportional to the contact force F and therespective frictional coefficients of the materials. F=Ff*μs (4). Thefrictional force should be maximized whilst ensuring that the appliedforce F does not produce plastic deformation of the components.

In one example, the following illustrates the deformation of componentswhen subjected to a temperature change. Once the thermal load producesthe expansion or contraction of a component, the component can beassembled and will match the size of a respective boss or cavity uponreaching thermal equilibrium.

A copper boss having a boss width of 1.5 mm was exposed to a temperatureof 210K for 1 second. The boss width shrank by approximately 0.02 mm.Therefore, the copper boss can be fit into a cavity having a 1.5 mmwidth, which then results in a leak proof, thermal interference fit whenthe copper boss returns to ambient temperature. A copper cover having acover width of 287 mm was exposed to 373K for 1 second. The cover widthexpanded by approximately 0.32 mm. Therefore, a core (for example)having a core width of 287 mm can be placed inside the cover, which thenresults in a leak proof, thermal interference fit when the cover returnsto ambient temperature.

Many different embodiments have been disclosed herein, in connectionwith the above description and the drawings. It will be understood thatit would be unduly repetitious and obfuscating to literally describe andillustrate every combination and subcombination of these embodiments.Accordingly, all embodiments can be combined in any way and/orcombination, and the present specification, including the drawings,shall be construed to constitute a complete written description of allcombinations and subcombinations of the embodiments described herein,and of the manner and process of making and using them, and shallsupport claims to any such combination or subcombination.

It will be appreciated by persons skilled in the art that the presentembodiment is not limited to what has been particularly shown anddescribed hereinabove. A variety of modifications and variations arepossible in light of the above teachings without departing from thefollowing claims.

1. A printed circuit board (PCB) cooling system comprising: a coreconfigured to be thermally coupled to at least one heat producingelectronic component on first side of the core; one or more channelsplaced on a second core side of the core, the first side of the core andthe second side of the core being opposite each other; a coverconfigured to couple to the core and to cover the one or more channels;wherein the core and the cover are coupled to form a substantially leakproof seal via a thermal interference fit; and wherein, when the coreand the cover are coupled, the one or more channels can be used totransport a working fluid.
 2. The PCB cooling system of claim 1, whereinthe core is a metal core printed circuit board.
 3. The PCB coolingsystem of claim 1, wherein the one or more channels comprise a fluidoutlet and a fluid inlet.
 4. The PCB cooling system of claim 3, whereinthe fluid outlet and the fluid inlet are placed on the first side of thecore.
 5. The PCB cooling system of claim 1, wherein the cover comprisesa peripheral, raised wall configured to couple to a peripheral edge ofthe core.
 6. The PCB cooling system of claim 1, wherein the thermalinterference fit results from cooling the core and fitting the coreinside the cover.
 7. The PCB cooling system of claim 1, wherein thethermal interference fit results from expanding the cover by heating thecover, and then fitting the core inside the cover while the cover isexpanded.
 8. The PCB cooling system of claim 1, wherein the channels areconfigured to transport water as the working fluid.
 9. A method ofmanufacturing a cooling system, the method comprising: providing a corehaving a first core side and a second core side; providing surfacechannels on the second core side; providing a cover configured to coverthe surface channels; and coupling the core and the cover with aninterference fit.
 10. The method of claim 9, wherein the core is a metalcore printed circuit board.
 11. The method of claim 9, wherein the firstcore side is configured to be in thermal communication with a printedcircuit board.
 12. The method of claim 9, wherein a distribution of thesurface channels on the second core side is determined, at least inpart, on a distribution of electronic components placed on the firstcore side.
 13. The method of claim 9, wherein the surface channels arecoupled to a fluid inlet and to a fluid outlet, and wherein said fluidinlet and said fluid outlet are placed on the first core side.
 14. Themethod of claim 9, wherein the cover comprises a peripheral raised wallconfigured to couple to a peripheral edge of the core.
 15. The method ofclaim 9, wherein coupling the core to the cover with an interference fitcomprises shrinking the core by cooling it, then placing the core insidethe cover.
 16. The method of claim 9, wherein coupling the core to thecover with an interference fit comprises expanding the cover by heatingit, then placing the core inside the cover.
 17. A cooling systemcomprising: a core having a first core side and a second core side, thefirst core side and the second core side being opposite each other; oneor more channels placed on the second core side; a cover configured tocouple to the core and to cover the one or more channels; wherein thecore and the cover are coupled to form a substantially leak proof sealwith an interference fit; and wherein, when the core and the cover arecoupled, the one or more channels can be used to transport a workingfluid.
 18. The cooling system of claim 17, wherein the first core sidecomprises a printed circuit board.
 19. The cooling system of claim 17,wherein the first core side is configured to be in thermal communicationwith a printed circuit board.
 20. The cooling system of claim 17,wherein the interference fit is the result of a thermal fitting.